1. Field of the Invention
The present invention is directed to the technical field of an insulation displacement connector having contacts for fitting cores of electric wires with insulation displacement, and particularly relates to an insulation displacement connector which is provided with a retainer for retaining contacts so that the contacts are prevented from dropping out from the connector housing when the contacts are subjected to a drawing-out force or compressive force from the electric wires. Here, the drawing-out force means a force mainly containing a force acting in the longitudinal direction of the contacts and in a direction of drawing the contacts out from the connector housing, and the compressive force means a force mainly containing a force acting in a direction perpendicular to the longitudinal direction of the contacts.
2. Description of the Related Art
Conventionally, a crimped style connector having contacts for crimping cores of electric wires has been used widely. The crimp style connector has a box-like connector housing, and contacts received in cavities piercing the connector housing. The work needed for crimping electric wires to the crimp style connector is carried out by the steps of: overlapping end cores of electric wires with end portions of the contacts; caulking a barrel on the cores while plastically deforming the barrel by a crimping tool; and inserting the contacts including an electric wire one by one into the cavities of the connector housing. There has been proposed a retainer for retaining contacts so that the contacts are prevented from being dislodged from the connector housing when the contacts undergo a drawing-out force from the electric wires. The retainer has stopper portions for being inserted into the cavities to press the contacts, and engaging portions to be engaged with the connector housing. Hence, the contacts are pressed by the stopper portions, and the contacts are prevented from dropping out from the cavities even in the case where draw-out force from the cavities acts on the contacts.
An insulation displacement connector having contacts for fitting cores of electric wires with insulation displacement has been used widely. In the condition that all the contacts are inserted into a connector housing, all the electric wires are simultaneously forced into slots of the contacts by an insulation displacement machine, so that the insulation displacement of the electric wires to the insulation displacement connector is performed. Hence, the number of steps can be reduced compared with the work required for crimping electric wires to form a crimped style connector. Hence, the machining cost can be reduced. Moreover, shortening of the time of delivery of such a connector including an electric wire can be achieved. This difference is remarkable in a multi-pole connector in which a large number of contacts are incorporated in one connector.
If the aforementioned retainer for a crimped style connector is applied to the insulation displacement connector, the contacts cannot be prevented from becoming dislodged. This is because there is a risk that the contacts may be removed from the cavities or the electric wires may be removed from the slots of the contacts when a compression force from the electric wires acts on the contacts in the direction of opening the electric wire insertion holes. This risk occurs because the electric wire insertion holes communicating with the slots of the contacts are opened up to the inlets of the cavities in an outer wall of the connector housing of the insulation displacement connector.
The present invention is designed bearing in mind this respect and an object of thereof is to provide an insulation displacement connector including a retainer in which: a turned-down portion of a retainer is fitted to hood portions, including opened electric wire insertion holes, provided at an end of an outer wall of a connector housing to thereby press contacts against the end of the outer wall. The connector housing is held by holding portions continuing to opposite sides of the turned-down portion and the holding portions are engaged with the connector housing against a direction of drawing-out of the contacts to thereby prevent the contacts from dropping out from the connector housing when the contacts undergo a drawing-out force or a compression force from the electric wires.
In order to achieve the above object, the insulation displacement connector including the retainer according to a first aspect of the invention has a feature that the insulation displacement connector comprises: male or female contacts each having a connection portion and slots, the connection portion being provided at a front end so as to be brought into contact with a partner contact under the assumption that a lengthwise direction is regarded as a front-rear direction, the slots being disposed on a side more rearwardly located than the connection portion and being opened in a heightwise direction perpendicular to the front-rear direction, the slots being provided for fitting a core, at a front end, of a corresponding electric wire inserted from the heightwise direction; a connector housing including cavities, hood portions and electric wire insertion holes, the cavities being formed so as to pierce the connector housing in the front-rear direction and being provided for receiving the contacts, the hood portions being disposed at one end in the heightwise direction and being formed to protrude rearward from a rear end of an outer wall on the side where the slots are opened, the electric wire insertion holes being opened in the outer wall in an area ranging from portions corresponding to the slots to rear ends of the hood portions respectively; and a retainer including a turned-down portion, a pair of holding portions and a pair of engaging portions, the turned-down portion being U-shaped so that a section which is cut by a plane facing a widthwise direction strides over the hood portions based on an assumption that a direction perpendicular to the front-rear direction and to the heightwise direction is regarded as the widthwise direction, the turned-down portion being fitted to the hood portions and extending in the widthwise direction so that a front end of an inner portion located in the inside of the hood portions presses the contacts from a back side, the pair of holding portions being provided at opposite ends, in the widthwise direction, of the turned-down portion and being bent like an L figure and an inverted L figure when viewed from a front-back direction so as to hold opposite end portions, in the widthwise direction, of the connector housing, the pair of engaging portions extending frontwardly from the holding portions respectively so as to be engaged with the connector housing.
First, when contacts are received in the connector housing without any retainer attached, front ends of electric wires are inserted through electric wire insertion holes and fit to slots of the contacts with insulation displacement. Then, a retainer is attached to the connector housing. That is, the turned-down portion of the retainer is fitted to the hood portions of the connector housing, widthwise opposite end portions of the connector housing are held by the holding portions, and the engaging portions are engaged with the connector housing. In such a manner, because the front end of the inner portion of the turned-down portion presses the contacts from the rear side, the contacts never become dislodged from the connector housing even in the case where the contacts suffer draw-out force from the electric wires. Moreover, even in the case where the contacts suffer compressive force from the electric wires in a direction toward the opened electric wire insertion holes, that is, in one heightwise direction, the turned-down portion receives this force, the hood portions fitted to the turned-down portion next receive this force, and the connector housing last receives this force through the holding portions. Hence, there is little force acting on the contacts so that the contacts can be prevented from becoming dislodged from the connector housing.
The insulation displacement connector including the retainer according to a second aspect of the invention has a feature wherein in the configuration stated in the first aspect of the invention, an outer portion of the turned-down portion is shaped like a plate parallel to the outer wall of the connector housing and extends frontward so as to cover the electric wire insertion holes.
In such a manner, external appearance becomes fine and elegant because the contacts and the insulation displacement portions are covered with the outer portion of the turn-down portion. Moreover, safety is improved because contact with a conductor can be prevented when the conductor is present in the periphery.
The insulation displacement connector including the retainer according to a third aspect of the invention has a feature that in the configuration stated in the first or second aspect of the invention, each of the holding portions has a vertical wall and a horizontal wall, the vertical wall extending in the heightwise direction toward an outer wall opposite to the outer wall having the electric wire insertion holes opened, the horizontal wall extending in the widthwise direction from an end of a vertical wall toward a vertical wall of the other holding portion; each of the engaging portions is provided so as to continue to a front side of the vertical wall and has a hook provided at its front end so as to be bent toward a heightwise direction or toward the widthwise direction; rails extending in the front-rear direction are provided in respective end portions, in the widthwise direction, of the connector housing; and engaged portions hooked by the hooks are provided at front ends of the rails or near the front ends of the rails in the connector housing.
In such a manner, when the retainer is to be attached to the connector housing, the engaging portions are brought into contact with the rails and moved forward, and the engaged portions are hooked by the hooks. In this condition, the rails are received by the horizontal walls of the holding portions.
The insulation displacement connector including the retainer according to a fourth aspect of the invention has a feature that in the configuration stated in any one of the first to third aspect of the invention, the insulation displacement connector including the retainer further comprises a holding mechanism for holding the contacts in the connector housing.
In such a manner, because the contacts are held in the connector housing by the holding mechanism, the contacts can be primarily prevented from becoming dislodged from the connector housing even in the case where the contacts are subjected to drawing-out force or a compression force from the electric wires. Moreover, because the contacts are more intensively retained in the connector housing by the retainer, the contacts can be prevented from becoming dislodged from the connector housing even in the case where more intensive draw-out force or compressive force from the electric wires is received.